Polyurethane foam materials

ABSTRACT

The invention is concerned with the production of polyurethane foams of the kind formed by reaction between a polyisocyanate (which term includes a di-isocyanate) and a glycol ester of a tribasic adduct obtained by reaction between a reactive dienophile e.g. maleic anhydride and an unsaturated fatty acid or ester. The process of the invention is directed to the production of polyurethane foams of that kind which are of finer cell structure and are less friable than previous foams of this kind by a more economic method which also avoids the distillation of unreacted acids from the tribasic adduct reaction product.

United States Patent Crawford et al.

1151 3 ,644,237 1 Feb.22, 1972 i541 POLYURETHANE FOAM MATERIALS [72] inventors: Raymond V. Crawford, Liverpool; Gavin E. Roscoe, Formby, both of England [21] Appl. No.: 802,656

301 Foreign Application Priority Data 7 Mar. 8, i968 Great Britain ..1 1324/68 [52] U.$.CL 260/15 AM,260/1BTN [51] Int. Cl. "088 22/44, C08g'53/l0 [58] Field oi Search ..260l2.5 AM, 2.5 AN

[56] Reierences Cited UNITED STATES PATENTS 3,068,254 12/1962 Le Bras et al ..26OI407 3,252,924 5/1966 Merten et al. ..260/2.5 2,591,884 4/1952 Simon et al ..260/2.5 2,602,783 7/1952 Simon et a1 ..'..260/2.5 2,698,838 l/l955 Simon et al ..260/2.5

2,811,493 10/1957 Simon et alum... 260/25 FOREIGN PATENTS 0R APPLICATIONS 1,032,233 6/1966 Great Britain "26012.5 1,032,365 6/1966 Great Britain... ..260I2.5 1 964,51 8/l964 Great Britain ..,..26o/2.s ux

Primary Examiner-Donald E. Czaja Atsistant Examiner-H; S. Cockeram Attorney-Imirie. Smiley, Snyder and Butrum [57] ABSTRACT The invention is concerned with the production of polyua reactive dienophile e.g. maleic anhydride and an unsaturated fatty acid or ester. The process of the invention is directed to the production of polyurethane foams of that kind which are of finer cell structure and are less friable than previous foams of this kind by a more economic method which also avoids the distillation of unreacted acids from the tribasic ade duct reaction product.

7Claims, NoDrawiw' --'of the foam obtained.

POLYURETHANE FOAM MATERIALS in prior British Pat. No. 1.032.365 there has been described the production of polyurethane foams by the reaction between a dior polyisocyanate and the glycol ester derived from reaction between a glycol and a tribasic adduct derived by combination of a reactive dienophile. e.g., maleic anhydride with an unsaturated fatty acid or'ester. ln this reaction unreacted unsaturated fatty acids were removed by distillation. a step which tends to increase the cost of the foamed materials. it has now been found that there is no need for the distillation step but the foam products so obtained tend to have a coarse cell structure and are rather friable.

It is an object of the present invention to avoid the disadvantages of the process referred to and to provide a polyurethane foam which is less friable. has a finer cell structure and is more economically produced by using mixtures of unsaturated fatty acids without distillation of any unreacted acids and using a limited amount of dienophilic dicarboxylic acid.

According to the invention there is provided a process for the production of polyurethane foam materialswhich comprises reacting a polyisocyanate (which term includes a di-isocyanate) with a polyol in the presence ofa blowing agent. said polyol being formed by reaction between (A) unsaturated fatty acids or esters thereof and/or rosin acids. (B) a dienophilic dicarboxylic acid or anhydride orester thereof and (C) a polyhydric alcohol. the ratio of component (B) to component (A) being from l:l6 to 1:30 by weight and the polyhydric alcohol being present in excess of the stoichiometric amount required to esterify the polybasic acid formed by reaction between components (A) and (B).

Component (A) may consist of the glycerides of the unsaturated fatty acids in the form of natural fats or the acids may be in the free state or as alkyl e.g.. methyl. esters. Thus for example this component may comprise tall oil fatty acids or crude tall oil. The unsaturated fatty acid may however be replaced wholly or in part by rosin acids. A preferred mixture for the reaction with the dienophile is one consisting of tall oil fatty' acids with a content of from 20-50 percent rosin acids. The content of unsaturated acid in component'(A) should be at least l percent by weight.

'Maleic anhydride is the preferred dienophilic dicarboxylic component, other examples of which are dimethyl maleate. itaconic acid or fumaric acid.

The polyhydric alcohol component (C) may be for example glycerol. trimethylol propane. hexane triols trimethylolethane.

alkylolamines. e.g. diethanolamine or mixtures of polyhydric alcohols may be used. e.g. mixtures of glycerol and foamforming polyether polyols.

In the process in accordance with the invention the reactants to form the polyol can generally be combined in any order. for example (i) all components can be reacted together. (ii) the polyhydric alcohol. e.g. glycerol. can be reacted with the unsaturated fatty acid before the dienophilic dicarboxylic component e.g. maleic anhydride is added, or (iii) the unsaturated fatty acid can be in the form of a triglyceride or monoglyceride to which the dienophile is added and further glycerol can be added later. I

The glycerol or other polyhydric alcohol can be present in such excess that some of it is present in thefree form in the polyol reaction productor an excess can be added to the reaction product before reaction with the dior polyisocyanate. Such additions are made to increase the compressive strength The amount of polyhydric alcohol used is such that the ratio of hydroxyl to carboxyl groups is sufficient to give a product with OH value in the region of 200-700 mg.KOH/g. In the case of the higher hydroxyl values. part of thepolyhydric alcohol is present in the unesterifled state. This excess can be The temperature at which the additionis carried out may be between I60 and 320 C.. preferably between 240300 C. The processing time for this reaction may be from one-half hour to l2 hours.

A further refinement in the preparation of the polyol comprises the inclusion of polybasic acids. e.g. polymeric fatty acids and low molecular weight dibasic acids. for example phthalic anhydride. adipic acid. glutaric acid and sebacic acid in the reaction. When polymeric fatty acids are included these will be added only after reaction between component (A) and component (B) has been completed. i.e.. before or during reaction with component (C). A dialkanolamine. e.g.. diethanolamine. may also be added at the end of the reaction.

or added during the reaction to give a clear product.

For the production of the polyurethane foam material there may be present. in addition to the blowing agent. catalysts.

surfactants and fire-retardants. Examples of suitable blowing agents are water and low-boiling-point liquids. c.g. trichlorofluoromethane. methylene chloride,

dichlorodifluoromethane. 7

Examples of suitable catalysts are tin compounds.

triethylene diamine. triethylamine. dimethylethanolamine. or

tetramethyl butane diamine.

Examples of suitable surfactants are silicone surfactants and nonionic wetting agents.

EXAMPLE 1 v 300 parts by weight of tall oil fatty acids containing 25 percent rosin acids and 15 parts by weight of maleic anhydride were heated for 3 hours at 290-300 C. under atmospheric pressure and under a blanket of nitrogen- After cooling to 150 C.. I22 parts of glycerol was added and the mixture was heated at 200 C. under atmospheric pressure for 2 hours during which time some water distilled out. At this stagethe acid value was 40. The reaction mass was cooled to l20 C. and 32.5 parts diethanolamine was added with agitation.

The resultant product had an hydroxyl value of 458 rosin acids and 18.7 parts maleic anhydride were heated present during the esterification' reaction oradded to the esterified product. I

The addition of component (A) to component (B) may be carried out prior to the esteritication step or concurrently; I

' EXAMPLEZ 300 parts by weight of tall oil acids containing 25 percent together at 270 280 C. for 3 hours. After cooling to l50 C., l23 parts of glycerol was added and the resultant mixture processed for 6% hours at a temperature of 2l5 C. and then cooled to l20 C. and 15 parts of diethanolamine added. A

The reaction product had an acid value of 1S mg.KOH/g. and hydroxyl value 413 mgKOH/g.

EXAMPLE 3 with glycerol at 220?. C. for 5% hours and omitting the diethanolamine.

Thefinal acid value was l7 mgKOH/g. and hydroxyl value 368 mg.KOH/ g.

EXAMPLE 4 I 3 oarts tall oil fatty acids containing 25;.percent rosin acids and 18.7 parts maleic anhydride were heated togetheras in Example 3 after which 149 parts glycerol and 32 parts phthalic anhydride were added. The reactants were heated to a temperature of 225 C.. over 4 hours after which time the acid value was 14 mg.KOH/g. and the hydroxyl value 324 mg.KOH/g.

EXAMPLE 5 added. The resultant mixture was processed for 2% hours with a maximum temperature of 230 C. The reaction product had an acid value of 4.4 mg.KOH/g. and a hydroxyl value of 34S mg.KOH/g.

EXAMPLE 350 parts of water white rosin and 21.9 parts by weight maleic anhydride were heated together for 1 hour at 27O-280,

' C. The product was then esterified with 143 parts glycerol for 3 hours at 230 C. and parts triethanolaminewas added. after cooling to 120 C.. to give a product'of acid value. 5.2 mg.KOH/g. and hydroxyl value. 370 mg.KOH/g.

TABLE A.I1IE POLYESTERS PREPARED AS 1N EXAMPLES 1-10 WERE USED IN MAKING RIGID POLYURETHANE FOAMS AS SHOWN BELOW A C 1) E F t 11 J K L M N Polyol from Example 1 3 4 6 6 3 3 7 8 9 10 11 Formulation of foam component 1:

Polyester 37 6 46. 0 31. 2 46. 4 46. 4 Glycerol 4. 5 3.1 4. ll 4. 6 Vorunol" Cl260. 24. 1 3t. 0 24.1 24.1 5161019 9.5 utt'r. 4 0.4 0.36 (1.4 11.4 911066 4 0.4 0.35 (1.4 0.4 l)..\ 1.l A .4 .3 1.4 1.4 1.4 1.4 'I.(, .l:..l'. .2 5 14.2 12.4 14.2 14.2 'I.(..1-..\i 23,1 23,1 23.0 23.1 20.2 23.1 23.1 Ratio of component 1 to Dcsmodur" 4 (dlphenyl methane dlisocyanato 1:1 1:1 1:1 1:1 1:1 1:1 1:1 1:1 1:1 1:1 1:1 31 31 '45 32 25 48 31 18 2t! 28 185 185 240 123 140 176 146 120 162 165 2. 2.4 3.0 L2 2.3 11.4 2.1 3.0 2.2 2.6 3.0 omprcx lvr strength (lb./sq. in.) 39 39 44 33 30 l "Vornnol" CP260 rmd NC10-19 and polycther polyols made by Dow by weight.

Chemical Company. \"ornnol" C1'.!60 is prepared by the reaction of glyrt-t'inc and propylene oxide. "\ornnol" N C-104i1, which is also known as ornnol" SA-l049. is a polycthcr octol derived from sucrose. and contains about 12% 011.

1 S1-1066 is a silicone surfactant mode by General Electric Company. It is n ropolymer of n dlmeth 'lpolysiloxune and a polyoxyelkylene other.

Norris-1n the above Tnb 0A the figures given for the formulation of component 1 and the ratio of component 1 to Desmodur" V are parts EXAMPLE 6 The process was carried out as in Example 5 but instead of glycerol and phthalic anhydride. 326 parts 3-methylol. 2.4- pentane diol and 30.6 parts adipic. glutaric and succinic acid mixture as in Example 2 were added to the tall oil/maleic anhydride adduct. The mixture was then processed for 7 hours at a maximum temperature of215 C.

The product had an acid value 27.5 mg.KOH/g. and hydroxyl value 300 mg.KOH/g.

EXAMPLE 7 EXAMPLE 8 840 parts crude lard and 40 parts maleic anhydride were heated together at atmospheric pressure for 3 hours at 280-300 C., cooled to 150 C. and 220 parts glycerol and 0.07 parts litharge were added. The mixture was then processed at 220-225 C. until a 1:1 mixture with methanol produced a clear solution. After cooling to 120 C.. 40 g. diethanolamine was added to give a product with an acid value 5.3 mg.KOH/g. and a hydroxyl value 365 mg.KOH/g.

EXAMPLE 9 640 parts of acidified sunflower oil foots and 40 parts by weight maleic anhydride were heated together as in EXAM- PLE 3. at the end of which time 200 parts of glycerol were Dmmodufl' and \orenol" are registered trademarks.

"Desmodur 44V" ls besieell dlpheny1enemethsnc-4.4-di-lsocyannto, and is described in the Buyer ocket Book (or the Plastic Industry. 3rd Edition. 1963. page 47. published by Ferbeniabriken Bayer. A.0.

D.M.E.A. is dimethylethenolamine.

'I.C.E.P. is trlchloroethyl phosphate.

'l.C.1-.M. is trlchloroiluoromcthane.

We claim:

1. A polyurethane foam made by the processwhich comprises reacting an organic polyisocyanate with a'polyol in the presence ofa blowing agent. the said polylol having a hydroxyl number of 200 to 700 and being formed by reaction between (A) a substance selected from the group consisting of unsaturated fatty acids. unsaturated fatty acid esters. and rosin acids. the content of unsaturated acid in this component being at least 15 percent by weight. (8) a substance selected from the group consisting of dienophilic dicarboxylic acids. their esters and their anhydrides and (C) a polyhydric alcohol. the ratio of component (B) to component (A) being from 1:16 to 1:30 by weight and the polyhydric alcohol being present in excess of the stoichiometric amount required to esterify the polybasic acid formed by reaction between component (A) and component (B).

2. The polyurethane foam of claim 1 wherein low molecular weight dibasie acids are also included inthe reaction components for forming the polyol. V

3. Thepolyurethane foam of claim 1 wherein polymerized fatty acids are added to the reaction components forming the polyol after reaction between component (A) and component (B) has been completed.

4. The polyurethane foam of claim 1 wherein a dialkanolamine is added to the reaction components forming the polyol at any time up to and including the end of the polyolt'orming reaction.

5. The polyurethane foam ofelaim 1 wherein during the reaction between the polyol and the organic polyisocyanate. catalysts surfactants and fire-retardants are present.

6. The polyurethane foam of claim [wherein a polyhydrie alcohol is added to the polyol reaction product before the polyol is reacted with the organic polyisocyanate.

I. The polyurethane foam of claim 1 wherein component (A) comprises a mixture of to 50 percent by weight of tall oil fatty acids and 20 to 50 percent by weight of rosin acids.

' O Q C C 

2. The polyurethane foam of claim 1 wherein low molecular weight dibasic acids are also included in the reaction components for forming the polyol.
 3. The polyurethane foam of claim 1 wherein polymerized fatty acids are added to the reaction components forming the polyol after reaction between component (A) and component (B) has been completed.
 4. The polyurethane foam of claim 1 wherein a dialkanolamine is added to the reaction components forming the polyol at any time up to and including the end of the polyol-forming reaction.
 5. The polyurethane foam of claim 1 wherein during the reaction between the polyol and the organic polyisocyanate, catalysts surfactants and fire-retardants are present.
 6. The polyurethane foam of claim 1 wherein a polyhydric alcohol is added to the polyol reaction product before the polyol is reacted with the organic polyisocyanate.
 7. The polyurethane foam of claim 1 wherein component (A) comprises a mixture of 80 to 50 percent by weight of tall oil fatty acids and 20 to 50 percent by weight of rosin acids. 